I'm applying for programs starting Fall 2017. I have my application list mostly finalized, but I wasn't sure if it was too top heavy. I feel like I have a fairly strong application, but I've heard particle physics (especially theory) is very competitive. Any help/input would be appreciated!

GRE Scores : (revised)Q: 168V: 170W: 4.0P: Not yet taken, but estimating somewhere in the 900s based on practice exams

Research Experience: 2.5 years in astroparticle physics at home institution (mostly computer work, no presentations or publications but will have an honors thesis). I also spent a month in New York helping build a prototype telescope.

I think your profile will set you up to be competitive at every school you're interested in / have a good fit with. So, if there is a school that you think you would like to be at, apply there! Don't worry about being "top heavy" because in order to get into a good school, you need to apply to a lot of good schools.

That said, it is certainly a good idea to have one or two middle tier and safety school. I don't know too much about HEP rankings to know which ones on your list that meet this criteria. But since you have 10 schools on your list, based on your profile, my recommendation is to go for:

7 or 8 schools that really interest you, no matter how high rank they seem to be1 or 2 schools that are in the middle (i.e. you're not sure you will get in but you think you have a good chance)1 school that is truly safety (>90% certainty of getting in).

I would also say if you find more schools you're interested in, then add them to the list instead of removing another school (unless you lose interest in a school between now and application time).

Finally, before you worry about safety schools, you (well, everyone, I think) should really think about what would you do with that acceptance. A safety school is meant to be "I would rather go here than nowhere at all". So, for many people I might recommend skipping the safety school if their plan is to just reapply next year if they don't get into a school of their choice, or if they plan to pursue a non-grad school path (for now) if they don't get into a school of their choice. Grad school is a big investment (of time, effort, giving up other opportunities) so I'm not sure a "safety school" mindset is a good one: personally, I would not go to a grad school that didn't excite me, even if it's my only offer.

Thanks for the response! Your advice made a lot of sense, especially the part about safeties. While I would be happy to attend most of the schools on my list, I realized there were one or two I wasn't really excited about, so there's not much sense in applying to them (and I found a couple more that really interest me).